Oxo preparation of high molecular weight alcohols



Oct. 29, 1957 R. B. MASON 2,311,567

oxo PREPARATION OF HIGH MOLECULAR WEIGHT ALCOHOLS Filgd March 9. 1954 CATALYST l MODIFIER] 1 7 '5 5 TO 0 COBALTER OLEFIN 2 H2+CO Ralph 8. Mason Inventor By W Attorney x0 PREPARATION or HIGH MOLECULAR WEIGHT ALCOHOLS 'Ralph Burgess Mason, Baton Rouge, La., assignor to Esso Research and Engineering Company, a corpora- ..tion of Delaware Application March 9,1954, Serial No. 414,967 12 Claims. (Cl. 260-638) The present invention relates to the preparation of oxygenated organic compounds by the reaction of olefins with hydrogen and carbon monoxide in the presence of a carbonylation catalyst. More specifically, the present invention' relates to a novel process for producing high molecular Weight alcohols by this reaction in substantially higher yields than has hitherto been practicable.

It is well known in the art that oxygenated organic compounds may be synthesized from organic compounds containing olefinic linkages by a reaction with carbon monoxide and hydrogen in the presence of catalyst containing metals of the iron group in a two stage process in which predominantly aldehydes and minor proportions of ketones and alcohols are formed in a first step in the presence of a carbonylation catalyst comprising metals of the iron group and particularly cobalt, and the products from the first step may then-be hydrogenated in a second step to convert the organic carbonyl compounds containing one more carbon atom than the olefinic starting material to the corresponding alcohol. Likewise, if desired, the alde- "hydes may be converted to the corresponding fatty acids by oxidation. The second stage hydrogenation catalyst may comprise any known reduction catalyst such as -metallic supported or unsupported nickel, copper chromite, 'sulfactive catalysts such as oxides and sulfides of tungsten, nickel and molybdenum and the like.

P v The carbonylation or 0x0 reaction by which name this process is generally known, provides a particularly attractive method of preparing primary alcohols to supply the. large market for plasticizers, detergents, solvents and the like; Amenable to the reaction to a greater or less degree are long and short chained olefinic compounds,-

not only hydrocarbons but most other organic compounds.

having a carbon-to-carbon olefinic linkage such as unsaturated alcohols, acids, esters and the like. Straight and branch chained olefins such as propylene, butene, pentene, hexene, heptene, styrene, olefin polymers such as di and tri- ,isobutylene, hexene and heptene dimers, polypropylenes,

olefinic fractionsfrom the hydrocarbon. synthesis process,

thermal or catalytic cracking operations and other sources of hydrocarbon fractions containing such olefins may be used as startingmaterials depending on the nature of the' final product desired. The synthesis gas mixture fed to the first stage maybe any desired ratio of H2 to CO, preferably within the limits of 0.5 to 2 volumes hydrogen per volume of carbo'n'monoxide. The conditions for reacting olefins with the synthesis gases vary somewhat in accordance with the nature of the olefin feed, the reaction being generally conducted at pressures in the range of from. about 1500 to 4500 p. s. i. g. and the ratio of synthesis gas to olefin may vary widely; in general, about 2,500 to 25,000 cubic feet 'of Hz-i-CO. per'barrel' of olefin feed are "em- "ployed. I

The catalyst for the first stage of the process is usually employed in the form of an oil-soluble compoundof the catalytically active carbonylation metalo Thus there have R 2,811,567 Patented .Oct, 29,1957.

high molecular weight fatty acids such as stearic, oleic, naphthenic, linoleic and the like. Water soluble catalysts, such as cobalt acetate, chloride, and the like, have also been suggested. Catalyst concentrations may vary from about 0.5 to 5.0% by weight of the catalyst salt based on the olefinic feed. The first stage or carbonylation reaction is generally carried out at temperatures in the range of from about 250 to 450 F. depending upon the nature of the olefin and other reaction conditions. In general, the lower olefins will react at lower temperatures and react to a greater extent than the high molecular weight olefins. The carbonylation reaction is an exothermic one, with a heat release of the same high order or magnitude as in the hydrocarbon synthesis process, about 35 to KcaL/gram-mol olefinic double bond reacted and, therefore, careful temperature control is required in the reaction zone toprevent decompostion of cobalt carbonyl to metallic cobalt and also to prevent formation of secondary reaction products and undesired reactions, such as hydrogenation of the olefin, formation of hydrocarbon synthesis product, and the like. At 3000 p. s. i. g. (1500 p. s. i. g. CO partial pressure) cobalt carbonyl starts to decompose at an appreciable rate above 350 F., thus decreasing the concentration of active catalyst. On the other hand, temperatures are preferably kept above 300 F. so as to keep the reaction rate up to a reasonable figure to insure high olefin conversions at reasonable feed rates.

Versatile as this alcohol synthesis, or OX0 reaction is in the production of alcohols from olefins, the process in the past has not proved itself adaptable to the preparation in good yields of high molecular weight alcohols. These compounds are of particular importance commercially in the manufacture of detergents and a multitude of other purposes. It has been found that, as the molecular weight of the olefin increases, the conversion to the aldehyde falls off rapidly and, with olefins above about 20 carbon atoms, reaction rates are too slow and yields too low for a commercially feasible operation. This rate and yield decrease withincreasing molecular weight of olefin is particularly evident in the case of highly branched tion reaction.

been employed the salts of the metals such as cobalt and is passed to the carbonylation zone.

It is a further purpose of the present invention to produce these high molecular weight alcohols from olefins having a substantially lower molecular weight, which olefins are in considerably larger supply than high molecular weight olefins. I

Other and further purposes and objects of the present invention will become more apparent hereinafter.

It has hitherto been found that, accompanying the main carbonylation reaction, i, e., the reaction wherein .an olefin is converted to an aldehyde having one more carbon atom, there is. formed alargenumber of secondary reaction products, such as esters, aldols, polymers, ketones and the like. It has now been found that, by the addition of a reaction modifier, the aldehyde synthesis reaction is directed into a completely new channel and there is formed, in high yields, a primary alcohol product having 2n+2 carbon atoms, where an olefin with n carbonaton s Accompanying this reaction is the normal aldehyde synthesis reaction producing aldehydes' and alcohols having n+1 carbon atoms. Othersecondary reaction products are substantially absent; the normal reaction product also is formed to a substantial! car yla ionls ase is conducted in the .presencebf zinc compounds.

Theprocessitself isconventional save :iorthe use .of odifi men i ned b ve he zinecomp unds are salts of fat y acids, o es, hydroxide ca bona es, and also metallic salts of cobalt hydrocarbonyl- The e may be add d in e t er so t on was olids omapr ssurized h ppe T e solu ionmeth d employsone or. a combinanon of ate olefin feed, or react on product a thersolent. while the hoppermethod of add tionre mits the want n mal y ns luble compoun s suchas o ides and carbonates and me al.-

n a cordance w th the Pr sent inventi n, therefore. h is pa sed in o the firstage react on zone. along with the olefin, carbon monoxide, hydrogen, and cobalt carbonylation catalyst, a reaction ,rnodifier, preferably zinc. Though the latter may be added as ametal or as an insoluble compound, such as the oxide or carbonate, in apreferred embodiment of the invention, it is added in solution and preferably, as a salt thatis soluble in the reactants or reagents. Though cobalt may be added in any form, for the active catalytic agent is the hydrocarbonyl which is synthesized in the course of the reaction and which is soluble .in the olefin-aldehyde mixture, zinc does not form a carbonyl and hence, to derive the benefits associated with a homogeneous reaction system, an oil-soluble form of zinc, such as zinc oleate, is a particularly desirable reaction modifier.

The present invention will best be understood from the more detailed description hereinafter, wherein reference will be made to the accompanying drawing which is a schematic illustration of a system suitable forcarrying out a preferred embodiment of the invention.

Referring now to the drawing, an olefinic hydrocarbon is fed through feed line 2 to the bottom of primary reactor I. The latter comprises a reaction vessel preferably divided into discrete zones separated by trays and free space. The reactor is preferably packed with inert solids to facilitate gas-liquid contact.

Also passed into reactor 1 are cobalt carbonylation catalysts and zinc modifier catalyst. These may, if oil soluble, be dissolved in the olefinic feed and, in a preferred aqueous solution of zinc acetate or a slurry of zinc carbonate, zinc metal and the like may also be employed, though not as efiectively. Cobalt is generally added to the extent of 0.2% to 0.5% calculated as metal on olefin feed, while the zinc is added to the extent of 0.05% to 0.5 preferably 0.1% to 0.2%.

Simultaneously, a gas mixture containing H and CO in the approximate ratio of 0.5-2 volumes H2 per mole C0 is supplied through line 5 and flows concurrently with the olefinic and aldehyde product upwardly through rcactor I. The latter is preferably operated at pressures of about 2500-3500 p. s. i. g. and temperatures of 200 to 400 F.

Liquid oxygenated reaction products comprising aldehydes are withdrawn from the upper portion of reactor 1 through line 6. The product, which is at a temperature of about 300-375 F., is then passed to cooler 7, where the temperature is lowered to about 60-l20 F., and then passed to high pressure gas-liquid separator ;8. Herein separation of unreacted gases from liquid product occurs. The unreacted gases may be withdrawn through line 9,

and after scrubbing, may be recycled to the system via line 10,,or in part purged. Liquid aldehyde product containing high concentration of cobalt carbonyl is with- .drawn from high pressure separator 8 through line 12.

A portion of this stream is preferably passed via line 13 to aldehyde synthesis reactor 1 to supply both cooling and a portion of the catalyst requirements of that vessel, the amount of product recycled being a function of the amount of cooling required in the reactor. The recycled liquid is preferably added along the length of reactor 1.

Liquid aldehyde product not recycled to reactor 1 is passed through pressure release valve 14 and line 15. This material, containing dissolved cobalt carbonyl and zinc salts, is sent to a catalyst decomposition or decobalting zone, where in the presence of heat and steam, water, or dilute organic acid, the inorganic contaminants are removed from the aldehyde product in a manner known in the art.

The aldehyde product, substantially completely free of inorganic compounds, is then hydrogenated under conventional conditions to alcohols and the alcohol product fractionated to produce both the 11+] and the 2n+2 alcohols, as described.

The process of the present invention may be further illustrated by the following specific examples wherein a heptene fraction is treated with zinc and its compounds under oxonation conditions to yield a C16 alcohol product.

Table I Modified 0x0 synthesis operations Run No A B O D E F G H Feed C1 0lefin O O1elln C Olefin C Olefin C Olefin C O fi C1 Olefin C1 Olefin- Catalyst Cobalt Aee- Cobalt Ace- Cobalt Ace- Cobalt Ace- Cobalt Aoe- Cobalt Ole- Cobalt Ole- Cobalt 01etate. tate. tote. tats. tote. ate. ate. ate. Wt. percent 1 1 l 2 M (1111 Mossy zinc.- glue acetate. 6 gmc olcate.

$600 3,000 Cu Chrom- Ni.

mite. Production Distribution:

Wt. percent Hydrocarbon. 9.9 12.4 8.2. Wt. percent 0; Alcohol 37.7 29.0 28.2. Wt percent. Intermediate 5.6 4.3.. 6.7. Wt. percent 0 Alcohol 34.8 32.1 37.4. Wt. percent C n n 0. Wt. percent Bottoms 13.4 I 22.2 1 19.6.

I High bottoms yield-believed duo to still hold up.

modification, a mixture of cobalt and zinc oleate is employed and is dissolved in the olefin feed admitted through line 2. It is tobe understood thatother forms ofcobalt, such as an aqueous solution of a cobalt salt, i. e., cobalt acetate, or a slurry of oil-insoluble cobalt solids, such as cobalt oxide, metal, carbonate and the like, may be employed. Similarly, other forms of zinc, such as an These data show the marked directional effect in the production of C16 alcohol from C1 olefins when zinc is added, either as metal, acetate, or oleate. It will be noted that substantially less zinc salt is required than zinc metal. In general, it is much more desirable to employ zinc salts than the metal.

The use of zinc salts has several advantages which are obvious. With the zinc added as salts in either aqueous,

packing may have some additional "advantages, 'e. 'g.',

06 an increase in Ca alcohol with a concurrent decrease in Cm alcohol production is noted. The data are tabulated "iiiTableII. The large intermediate'cut in run K is caused-by poor hydrogenation --and the major portion of providing temperature control, etc., the metal as such 5 theflcut should be'creditedto Cis' alcohol product.

SUMMAIkYlTABLE 11 RunNo I J K L N Feed C1 Olefin C1 Olefin C1 Olefin C1 Olefin C1 Olefin O1 Olefin C1 Olefin.

Catalyst Cobalt Oleate. Cobalt Oleate. Cobalt Oleate. Cobalt Ace? Cobalt Ace- Cobalt Ace- Cobalt Acetate. tate. tate. tate.

Cagalyst Cone, Wt. percent 0.2 0.2 0.2 0.2 0.2 0.2.

Modifier Zinc Oleate. Zinc Oleate.-- Zinc Acetate Zinc Acetate Zinc Acetate. Zinc Acetate.

Wt. percent Modifier as Zn++ 0 0.2 0 0.2.-. 0. 0.05.; 0.025.

Temperature, F.

Pressure, P. s. l. g..

Reaction Time, Hrs

Hydro Product Distribution,

-Wt. percent: 1

Hydrocarbon 03 Alcohol Intermediate Q15 Alcohol C 5 Glycol Bottoms.

l 0x0 product hydrogenated in autoclaves over reduced Harshaw nickel catalyst using methanized hydrogen, 6hrs., 350 F. and 3000 p. s. i. g.

is expendable and will require replacement which will necessitate mechanical operations that will add to the cost of the process. In addition to this economic advantage the use of zinc salts as compared to the metal packed reactor offers possibilities of process control. As will-be seen in subsequent paragraphs the ratios of C16 and Cs alcohol can be controlled within limits by adjusting the concentration of zinc salt. A third distinct advantage for the use of zinc salt as compared to the metal packed react-or resides in the flexibility of the process. Thus, for example, it is possible to change from a process producing only Ca alcohol to one producing' both Ca and C16 alcohol merely upon addition of the modifier salt. Contrawise, when market require- Though the invention has shown at length the con version of heptenes to C16 alcohols, the invention is not restricted thereto. With higher boiling olefins corresponding higher boiling alcohols are produced, thus affording, for'example, economical preparation of C1s-C24 alcohols. By the straightforward Oxo reaction, low yields with C-C2s olefins renders the process uneconomical.

The advantages of the modified alcohol synthesis for the'production of high molecular weight alcohols is shown in Table III below. In this table there are compared the results obtained when a C15 olefin is oxonated and hydrogenated toproduce the corresponding Cm alcohol, and when a C1 fraction is oxonated in the presence ments for the higher boiling alcohol are non-existent, of azinc salt to produce the C16 alcohol.

TABLE III [0x0 Synthesis: 0lefln+1:1 Synthesis Gas] Fee C15 Poly-men--. C Polymer.. 0 Polymer. Catalyst Cobalt 0leate Cobalt Oleate... Cobalt Oleate.

Conc., Wt. percent on Fee 0.2 0.15-.. .25. Catalyst Modifier None Zinc Oleate- Zinc Oleate. 00110., Wt. percent on F I 0.15... 0.10. Reactor Temp., F 35 350 345 Feed Rate, v./v./hr 0.28 .32 .30. Pressure, P. s. i. g. 3,000- 3,050. 3,000. Total Olefin Conversion, percent. 33 61.5- 80.2. Total Alcohol Selectivity, percent:

Grams Cm Alc. Prod/100 g. Feed 28 29. 33. Grams C; Alc. Prod/100 g. F 0 34 51. Estimated Purity Cm Ale. Prod. 83. 98 Corrected C1. Ale. Yield/100 g. 0lefin. 23 28 It is thus demonstrated that a higher yield of C16 5 alcohol per unit weight of olefin feed can be obtained from the C7 feed with zinc olcate as a modifier. Furthermore, the alcohol product is of higher purity as determined from hydroxyl number determinations. A

still further advantage for the modified oxonation of C7 olefin is the substantial amount of Ca alcohol which is produced simultaneously.

In Table IV there is shown the marked superiority of zinc salts as compared to zinc metal in equivalent concentrations in the production of the dimeric primary a1- crease Cm alcohol formation. Below 0.2 wt. percent zinc cohol product.

TABLE IV Comparison of zinc metal vs. zinc salts as dimeric primary alcohol synthesis Zinc Acetate Cobalt Acetate Cobalt Oleate.-

2% Cobalt on Feed... 2% Cobalt on Feed 2% Cobalt on Feed.

Zinc Oleate Cr Olefin.

. Cobalt Acetate.

Mossy Zine Metal.

27 Zinc on Feed 2'7 Zinc on Feed... 27 Zinc on Feed. 353 and 355 3,000 p. s. 1. Syn. Gas 1 1 /13, Ratio).

Hours v 9 Wt. percent Principal Products:

0 Alcohol. Intermediate 5 ,7. 5.5. Cu Alcohol 35.4 37.4

1 Autoclave studies.

1 Based on distillation of hydrogenated: product.

1. The process for converting olcfinie compounds hav ing n carbon atoms in the molecule into primary a1 cohols having 2m+2 carbon atoms which comprises passing said olefin, H2, CO, a cobalt. carbonylation catalyst,

and a zinc comprising reaction modifier into a carbonylation zone, said zinc modifier being present in an amount sutlicient to substantially increase the yield of said' alcohols, maintaining, carbonylation temperatures and pressures. in said zone, withdrawing an aldehyde product from said zone, hydrogenating said product, and recovering in good yields a. primary monohydric alcohol having 2n+2, carbon atoms- 2. The process of claim 1 wherein said reaction modifier is. a water insoluble and. oil-insoluble form of zinc.

3. The process. of claim 2. wherein said modifier is zinc metal.

4. The processv of claim. 1.- wherein said reaction modifier is a. zinc salt- 5. The process of claim 4 wherein said reaction modifier is a water soluble. zinc salt.

6. The process of claim 4 wherein said reaction modifier is an oil-soluble zinc salt.

7. An improved process for producing high; yields of primary monohydric alcohols having 2n+2 carbon atoms from olefins having n carbon ,atoms which comprises passing said olefins, Hz, CO, a cobalt carbonylation catalyst and a solution of a zinc salt into a carbonylation zone, said zinc salt. being; present an amount sufficient to substantially increase the yield! ofsaid alcohols, maintaining temperature of from about 250-375 F. and pressures of from about 15004500 1). s. i. g. in

- said zone, withdrawing an aldehyde comprising reaction product from said zone, removing metal-comprising com ponents from said reaction product, hydrogenating said aldehyde product and recovering high yields of said primary alcoholproduct.

8 The process of claim 7 wherein said zinc salt is added to the extent of 0.05'-0.5 onolefin, calculated as zinc ion.

9-. The process of claim 7 wherein said zinc salt is ,zinc acetate dissolved in water.

10. The process of claim 7 wherein said zinc salt is zinc oleate dissolved in olefin.

11. The process of claim 7 wherein said cobalt catalyst is cobalt oleate.

12. The process of converting heptenes into primary isohexad'ecyl alcohols which comprises passing a heptene fraction into a carhonylation reaction. zone, passing Hz, CO and 0.2'-0.5% cobalt ol'eate, calculated as cobalt on olefin, into said 20116,. Passing 0.05'-0'.5 zinc oleate calculated as-zincinto said zone, said oleates being dissolved in said heptene fraction, maintaining temperatures of from about 250-375 F. and pressures of from 1500- 4500 p. s. i. g. in said zone, withdrawing, an aldehyde comprising reaction product, freeing said product of dissolved and suspended cobalt and zinc components, hydrogenating said aldehyde. product, and" recovering good yields of a primary isohexadecyl monohydric alcohol product.

References (Iited in the file of this patent UNITED STATES PATENTS Schexnailder Mar. 14, 1950 

1. THE PROCESS FOR CONVERTING OLEFINIC COMPOUNDS HAVING N CARBON ATOMS IN THE MOLECULE INTO PRIMARY ALCOHOLS HAVING 2N+2 CARBON ATOMS WHICH COMPRISES PASSING SAID OLEFIN, H2, CO, A COBALT CARBONYLATION CATALYST, AND A ZINC COMPRISING REACTING MODIFIER INTO A CARBONYLATION ZONE, SAID ZINC MODIFIER BEING PRESENT IN AN AMOUNT SUFFICIENT TO SUBSTANTIALLY INCREASE THE YIELD OF SAID ALCOHOLS, MAINTAINING CARBONYLATION TEMPERATURES AND PRESSURES IN SAID ZONE, HYDROGENATING SAID PRODUCT, AND RECOVERING IN GOOD YIELDS A PRIMARY MONOHYDRIC ALCOHOL HAVING 2N+2 CARBON ATOMS. 